Selecting CPU MODEL from .bochsrc automatically chooses real HW CPUID and also configures Bochs emulator to emulate this specific CPU including all its features only.
Supported CPUs to choose from:
core2_extreme_x9770
corei7_sandy_bridge_2600K
p4_prescott_celeron_336
Change CPUID to generic interface which could be chosen from .bochsrc.
Bochs CPU emulation will enable/disable features (like instruction sets) according to CPUID that is selected.
TODO: Add database of CPUID from real hardware CPUs